Manufacture of insulators for high-potential electric conductors.



UNITED s'rA'rEs PATENT OFFICE.

lrnnn M.ILOCKE, or vroroa, NEW'YORK.

MANUFACTURE OF INSULATOB'S FOB- HIGH-POTENTIAL ELECTRIC GONDUGTORS.

Specification of Letters Patent. vPatented Dec. 15,1914.

No Drawing. Original application filed March 9, 1909, Serial No. 482,382. Divided and this application filed June 2, 1914.

To all whom it may concern Be it known that I, FRED M. Lo'oKE, of.

Victor, in the county of Ontario, in the State of New York, have invented new and useful Improvements in the Manufacture of Insulators for High-Potential Electric Conductors, of which the following is a full,clear, and exact description.

"manufacture, the essential ingredients of which are boron or boron compound and porcelain'or glass thoroughly mixed bytrituration or levigation and then moldedand fired in the usual manner for porcelain or glass insulators. 3

The use of glass as an insulator for high potential electric conductors is recognized by manufacturers and users as being im-- practicable owing to its brittleness and susceptibility to breakage by varying temperatures or climatic conditions, and also from the dielectric stresses and resultant heat to which it is subjected. For this reason porcelain, which appears to have a greater dielectric strength and is less susceptible to breakage by variations in temperature or climatic conditions, is generally employed.

The primary object of my present inven-" tion is to increase the inductive capacity,

suitable quantity of boron or boron com-- pound, such as boracic acid, with the body of porcelain or'glass 'usually employed ,for. insulators, the inductive capacity, dielectric strength and resistance to puncture or dis integration by the electric current and sud- ,den temperature or climatic changes, are

increased approximately 20% over the same size and form of the'base of porcelain insulators. Fol-example, in the-experiments which I have-made to determine the relative specifiq, inductive capacity of air, 'glass,- po j SeriaI'No. 842,336.

tion, I find that the specific inductive capacity of this composition is three times as great as that of the commercial porcelain insulatorsof the same size and form; sixtimes'as great as glass, and twelve times as great as air.

In the tests which I have made to determine theresistance to puncture 'by high voltage, I find that where a porcelain insulator of the best quality was capable .of resisting 80,000 volts, an insulator made of my improved composition and of the same size,

andform as the porcelain insulator," withstood 100,000 volts, or 20,000 volts more than the porcelain insulator, which was due solely to the increased specific inductive capacity and dielectric strength produced by the boron compound. This high inductive capacity and dielectric strength which gives great toughness to the insulator, is prob ably due to the factv that boron and hydro? gen form no compound or compounds under fusion and except in one or two special.

instances and under special circumstances,

boron forms no compound whatsoever with hydrogen, thereby more effectively excluding moisture from the composition, which is believed to account for the high inductive capacity, dielectric strength, as well as non- 'puncturability and resistance to heat.

I The manufacture of high potential porcelain insulators is well understood, and in the formation of my improved composition the boron compound, such as boracic acid,

and porcelain ingredients, are thoroughly mixed in suitable proportions. The composition isthen molded while in a plastic con-v dition into the desired form of insulator and finished in the usual manner for making high potential porcelain insulators. What I claim is 1. An insulator comprising a porcelain base and a boron compound fused together to form alhomogeneous body.

, 2. An insulator comprising a porcelain -base having a boron compound incorporated therein. In witness whereof I have hereunto set my hand this 28th day of May 1914. 

